My Amp Gauge Has Never Worked Since I Bought The Car 5 Years Ago. I Tore Apart My Engine Wiring Harness Today To Find I Dont Have A Black With White Stripe Wire In My Harness,and That Is The Wire That Is To Make My Amp Gauge Work.yes I Have Center Councel Gauges From Factory.i Only Have 12 Wires In My Harness Schmatic Shows 13.my Question Is Should I Have 13 Or 12, And Where Would I Terminate The Black Wire With White Stripe?it Shows Horn Relay But Under #10 Red Hot Wire? Their Are 3 Small Wires Coming Off Bottom Of Relay Each Have Their Own Connecter.im A Electrician By Trade So I Cant Hire Anyone To Do My Own Job. Thank You.

The 3 small wires with their own connector are: Black= from horn button on steering wheel, green= to horns, pink w/bk stripe= key buzzer.
The ones you want are the screw lugs. One of your ammeter wires goes to a screw lug on the horn relay (both are the same point electrically) and the other goes to the lil junction block behind (in front of?? on the rad support!) the battery.

The wire to the ammeter (actually a millivolt meter) on a car with factory gauges actually is spliced into the harness where the wire from the alternator output connects to the cars wiring. One of these large wire then connects to the horn relay terminal, and the other wire runs into the fuse panel. The repro guages connect directly to the horn relay terminal. Both the repro and orignal wiring harness with guages have the other leg of the gauge connected to the terminal infront of the battery.

mark should i have 13 wires in harness or 12?if amp gauge is spliced in by factory does it run from horn relay all the way to pin connector at fire wall,and it should be black with white stripe.i have no such wire and i only have 12. im thinking i have wrong harness,or did gm take it through firewall another way? thank you

The factory harness has a black and white wire on the engine side lighting harness that runs from that splice to the bulkhead connector, and another that mates up with it in the under dash harness. The circuit runs thru the bulkhead connector on one of the terminals. I haven't counted the number of wires needed, but you have to have 2 wires for the ammeter to work.